Thibela releases TB study findings

South African TB research group on gold miners, Thibela, have released their findings into isoniazid...

The Gauteng Health Department. Picture: Nomsa Maseko/Eyewitness News

South African TB research group on gold miners, Thibela, have released their findings into isoniazid preventative (IPT) TB therapy among gold miners in South Africa.

The study consisted of screening for active TB and using

symptoms and a chest X-ray.

Any gold miner suspected of having active TB was referred

for TB treatment while individuals without active TB were offered nine months

of IPT.

The study group found:

  1. You do not always need an X-ray: In southern Africa, health workers and patients in rural areas often cannot access X-rays to confirm or rule out active pulmonary TB. Without X-rays to verify that patients did not have active TB, many physicians were unwilling to start patients on IPT.

Thibela found that health workers could exclude at least 90 percent of active TB cases through sputum testing and symptom screening - asking patients if they were experiencing night sweats, a persistent cough or weight loss.

Based in part on these findings, South Africa's latest IPT guidelines issued in June 2010 no longer require chest X-rays and TB skin tests to start HIV-positive patients on IPT.

However, in high TB prevalence settings, researchers noted that chest X-rays increased TB case detection.

  1. IPT and HIV: People living with HIV, which compromises the immune system, are up to 37 times more likely to develop active TB.

Findings from Thibela were able to confirm what many had long suspected but had failed to prove: that IPT provision to people living with HIV reduced their likelihood of dying.

In fact, Thibela researchers showed it halved the risk of death among HIV-positive patients on or just starting anti-retrovirals (ARVs).

Based on this finding, South African guidelines no longer discourage the use of IPT in ARV patients.

  1. Slamming side-effects: Although the World Health Organisation has recommended IPT since 1999, implementation was slow, partly due to challenges in TB screening and doctors' fears of possible side-effects, most notably liver damage.

Thibela researchers, however, found only a small number of cases of liver damage and these were among heavy drinkers. The most commonly reported side-effect of IPT was increased appetite.

  1. Ignorance is not always bliss: IPT roll-out has been slow globally but in South Africa, coverage was below 1 percent in 2010 - eight years after the country introduced the preventative therapy. Zambia has only recently begun piloting IPT.

Thibela researchers found that doctors were unwilling to prescribe the drug to patients because they did not know about the drug's TB prevention benefits and did not have experience in prescribing it. Some doctors said they preferred to wait to treat TB with more familiar drug courses than to prevent it.

  1. Mobilising men: Although Thibela eventually included about 27,000 mine workers, mostly men - 80,000 indicated they would be willing to participate in the study.

Thibela published research on the community mobilization and education strategies it used to get men on board in a November 2010 supplement of the medical journal, AIDS.

"The uptake we achieved was truly remarkable, especially when you consider it was almost an exclusively male population and men are notoriously poor adopters of health strategies," said Thibela's lead researcher and chief executive officer of South Africa's Aurum Institute for Health, Gavin Churchyard.

"We've shown that it is possible to mobilize an entire population to adopt a health prevention strategy."

Strategies that worked well to drive up men's willingness to participate included the use of peer educators, community events and incentives tied to project phases.

Less popular was the use of mobile-phone messaging due to frequent phone number changes, and treatment buddies, which sparked privacy concerns among actual trial participants.